The invention discloses a weighted Monte Carlo calculation method for
neutron kinetics. The method comprises the following steps that: 1: establishing an initial
particle source library, simulating initial particles, if the initial particles are neutrons,
jumping to 2, and if the initial particles are delayed
neutron precursors,
jumping to 4; 2: sampling time for the neutrons to generate
nuclear reaction, if the time exceeds transient
process time t,
jumping to 5, and otherwise, jumping to 3; 3: sampling to determine a type for the
neutron to generate the
nuclear reaction, if scattering reaction happens, keeping particle weight to constant, jumping to 2, if
adsorption reaction happens, changing the weight of a descendant particle, sampling to determine the existence state of the descendant particle, if the descendant particle is the neutron, jumping to 2, and if the descendant particle is the precursor, jumping to 4; 4: sampling precursor
decay time, if the time exceeds the transient
process time, jumping to 5, otherwise, changing a particle state into the neutron, and jumping to 3; and 5: carrying out statistics on the contribution of the particle, if particles which are not simulated are still in the presence in the source
library, jumping to 1, and otherwise, ending to output a result.